Pfft, just buy a Perbro Aerospace Zoomer Island Hopper. You can still go round Kerbin twice and do some cool stunts.
Definitely not an advertising attempt to persuade the company to buy some more island hopper varients.

Oh wow, that was quick! How the f**k did you get it round Kerbin twice??? And I only tested landing on water, I didn't know it could get off again. 1/6 throttle can be reached at 15km altitude by using a higher throttle to get up to speed then reducing it so that you are holding your speed, but only just.